Technical Field
Certain embodiments of the invention relate to a cryopump, a control method of a cryopump, and a cryocooler.
Description of Related Art
When a new cryopump is installed at a site, the cryopump is cooled from room temperature to a cryogenic temperature, and a vacuum exhaust operation starts.
In addition, as is known, since the cryopump is a gas storage type vacuum pump, regeneration is performed on the cryopump at a certain frequency in order to discharge the stored gas to the outside. In general, regeneration processing includes a temperature raising stage, a discharging stage, and a cooling stage. When the cooling stage ends, the vacuum exhaust operation of the cryopump is restarted. The cooling of the cryopump for preparing the vacuum exhaust operation may be referred to as a cool-down operation.